fix(slider): normalize value, reactive trackEl, aria-valuetext

src/shared/ui/Slider/Slider.svelte

@@ -87,7 +87,7 @@ const percent = $derived.by(() => {
     return Math.min(Math.max(((value - min) / (max - min)) * 100, 0), 100);
 });
 
-let trackEl: HTMLElement | undefined;
+let trackEl: HTMLElement | undefined = $state();
 let dragging = $state(false);
 
 /**
@@ -101,6 +101,20 @@ function commit(raw: number): void {
     }
 }
 
+/**
+ * Keep an externally-supplied value normalized to the step grid and range.
+ * Mirrors the bits-ui primitive's behavior so out-of-range or off-grid
+ * props don't desync the thumb position from aria-valuenow / the label.
+ * Converges in one pass: once snapped, the value equals its own snap.
+ */
+$effect(() => {
+    const normalized = snapToStep(value, { min, max, step });
+    if (normalized !== value) {
+        value = normalized;
+        onValueChange?.(normalized);
+    }
+});
+
 /**
  * Resolve a pointer event to a value using the live track rect.
  */
@@ -229,6 +243,7 @@ const thumbClasses = `block w-2.5 h-2.5 bg-brand
                 aria-valuemin={min}
                 aria-valuemax={max}
                 aria-valuenow={value}
+                aria-valuetext={String(format(value))}
                 aria-disabled={disabled ? 'true' : undefined}
                 data-active={dragging ? '' : undefined}
                 onkeydown={handleKeyDown}
@@ -276,6 +291,7 @@ const thumbClasses = `block w-2.5 h-2.5 bg-brand
                 aria-valuemin={min}
                 aria-valuemax={max}
                 aria-valuenow={value}
+                aria-valuetext={String(format(value))}
                 aria-disabled={disabled ? 'true' : undefined}
                 data-active={dragging ? '' : undefined}
                 onkeydown={handleKeyDown}